Elastic Frictional Isometric Type Exercising Device

Abstract

An exercising apparatus in which a handle is connected at one end of a flexible elastic strand such as nylon, the opposite end portion of the strand being supported by a base having spaced stationary abutments thereon adapted to be frictionally engaged by the strand when tensile stress is applied to the latter through the handle. The apparatus is further characterized by a frictionally engaged second strand for damping the return of the first strand from its stressed elongated position to its initial unstressed contracted position.

Description

This invention relates to push and pull exercising apparatus and more especially to exercisers designed to require the use of cantilevered stresses during various postures of exercise.

Heretofore, exercisers have been provided for developing human muscles in accordance with the concept of progressive resistance wherein the subject exerts direct colinear force upon an elastic or resilient element, and also in accordance with the concept of isometric contraction wherein a similar direct force is exerted upon a substantially immovable object (See, for example, U.S. Pat. Nos. 3,117,781 and 3,337,215). So far as applicant is aware, however, none of such prior art devices require the use of a cantilevered force for exercising, that is, the employment by the subject of what is commonly termed as "shovelling" action: and none have apparently employed a snapback damping means in association with cantilevered exercising stresses.

It is therefore an object of this invention to provide a frictional isometric exercising apparatus adapted to offer a resistive force to the user during various types of physical exercise.

It is another object of this invention to provide an exercising apparatus of the type described in the immediately preceding paragraph wherein the stress resisting element comprises a flexible elastic strand embodying the dual concept of initial progressive resistance followed by isometric contraction.

It is another object of this invention to provide an exercising device in which cantilevered stress is transmitted by the dual-concept strand from one end of a grasping bar to a base, said strand having a major segment of its effective length confined for longitudinal elongation and contraction within the base thereby permitting the use of a relatively long strand having a relatively small unit elongation for providing an aggregate strand expansion of the desired amount. Ordinarily, the aggregate strand expansion required for satisfactory use of the device is only a few inches but due to the small unit elongation of strand materials capable of assuming an isometric condition following a short phase of progressive resistance, considerable total strand length is required.

It is another object of this invention to provide a simple unique means for adjusting that portion of the effective strand length disposed between the end of the grasping bar and the base of the apparatus.

It is another object of this invention to provide a snapback damping device for frictional isometric exercisers, which device damps sudden return of a strand from its stressed elongated position to its unstressed contracted position.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which,

FIG. 1 is an isometric view of one embodiment of an exercising apparatus according to my invention;

FIG. 2 is an inverted view of the base of the apparatus, showing the cable or strand-receiving compartment and with the base cover removed;

FIG. 3 is a transverse sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a transverse sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is an enlarged detail view of the connection between one end of the grasping bar and the strand, showing means for adjusting the effective overall strand length;

FIG. 6 is a view similar to FIG. 2 showing a modified form of base construction;

FIG. 7 is a sectional detail view taken along line 7-7 in FIG. 6, showing a typical antifriction roller for longitudinally supporting the strand and also showing a portion of the strand compartment cover in position and

FIG. 8 is a fragmentary view of a modified type of grasping handle adapted to offer a counterrotational resistance to the torque of the tensioned strand wound thereon.

Referring more specifically to the drawings, the numeral 10 broadly denotes an exercising apparatus comprising base 11, strand assembly 12, and an elongated grasping bar 13. The base 11 has a relatively flat upper surface 11a and a depending perimetrical rim 11b which surrounds a strand storage compartment 11c. A compartment cover 14, which also serves as a bottom for the base, is removably secured in position as at points 14a (FIG. 2).

One end of a resistive strand portion 12a of assembly 12 is anchored within compartment 11c as at 16, said strand portion being made of a material such as nylon and characterized by an elasticity which progressively decreases with the increase of tensile stress therein until a substantially immovable isometric condition exists. Although strand nylon and similar plastic strands are sometimes regarded as relatively nonelastic, it is well known that certain formulations possess the above-described limited elastic characteristics during the initial stress and the nonelastic characteristics when further stressed. Since a suitable strand must possess these dual characteristics, the unit elongation is relatively small and, therefore, it bc becomes necessary to employ a relatively long strand to obtain the required elongation for proper utilization of the apparatus. Hence, the strand compartment 11c is equipped with spaced abutments 17 about which strand portion 12a is wound and subdivided into a plurality of angularly disposed shorter segments so that the length may be supported for longitudinal expansion and contraction in a relatively small space.

The end of strand portion 12a remote from the anchor point 16 extends upwardly through opening 18 in base 11 and has an eye or ring 19 secured thereto, said eye being adapted to receive a clip 20 on the lower end of strand portion 12b (FIG. 1).

Strand portion 12b, when tensioned, extends upwardly from clip 20 and has its upper end secured as at 21 to an eye bolt 22 on one end of grasping bar 13 (FIGS. 1 and 5). In order to reduce or increase the length of strand between bolts 22 and the base opening 18, the strand portion 12b may be wound around bar 13 the desired number of turns, then strand loop 25 is formed and drawn through the eye or perforation 22a of bolt 22, first to the dot-dash line position and then to the bold line position around the neck of the bolt, thereby securely anchoring the adjusted strand to the bar end.

The anchoring loop 25 may be dispensed with if a modified type of handle 15 is employed as shown in FIG. 8. Handle 15 consists of an elongated grasping portion 15a and an eccentrically disposed end portion 15b around which portion 12b is wound and to which portion 12b is anchored as at 21 in the same manner as in FIG. 5. By providing the eccentrically disposed handle end portion 15b, the tension in strand portion 12b tending to unwind it, will be counteracted by the leverage provided by the offset of portion 15b.

A snapback damping means is operatively associated with strand portion 12a to protect the user from injury resulting from sudden relaxation of effort when the strand is highly stressed. The damping means comprises an elastic takeup strand 26 having one end thereof secured as at 27 to strand portion 12a and its other end secured as at 28 to base 11, said strand being sufficiently elastic to take up the maximum permissible elongation of strand portion 12a disposed between points 27 and 16 (FIG. 2), and also relatively more elastic than portion 12a. Between points 27 and 28, aligned spaced pegs or abutments 29 are secured to base 11 for frictional engagement with strand 26. Similar pegs or abutments 30 in alignment with abutment 28 provide means for adjusting the length of strand 26.

It will be noted in FIGS. 1 and 2 that the strand 26 is in contracted position during which the slack between points 16 and 27 in strand portions 12a is taken up or transferred to the strand length between point 27 and the end of handle 13.

During use of the apparatus, the subject stands upon base 11 and grasps bar 13 at longitudinally spaced points 31 and 32 (FIG. 1); and then proceeds with various physical exercises while exerting an upward and/or lateral pull upon strand assembly 12. The initial upward pull from the position shown in FIG. 1 will be resisted gradually or mildly by takeup strand 26. After the slack has been absorbed, a continued upward pull by the user will be resisted also by strand portion 12a during which the latter will be elongated throughout its length until a substantially isometric condition exists. The progressive initial resistance offered by strand portion 12a will be modified by the cumulative frictional contacts between the strand portion and successive abutments 17.

It is important to note that the frictional contact between strand 26 and abutments 29 serve to damp or decelerate the rate of return of strand portion 12a from a tensioned extended position to its untensioned contracted position, thereby preventing possible injuries such as dislocation of joints and sprained muscles in the event of sudden termination of a major exertion of effort by the user.

In the subject's posture as shown in FIG. 1, the grasping bar 13 acts as a lever fulcrumed intermediate its ends as at 31 upon the right hand so that the bar end adjacent the strand assembly 12 is cantilevered and the opposite bar end counterbalanced at 32 by the left hand. Thus, the right arm will be subjected to tensile stress and the left arm to compressive stress. By varying the position of the right hand along bar 13, the cantilevered movement of force may be varied as desired by the user. Obviously, variations of physical posture may be assumed by the subject to exercise body muscles with cantilevered stress according to the invention.

FIG. FIGS. 6 and 7 illustrate a slightly modified form of strand supporting and strand housing base in which the damping means 26 is omitted, but with a takeup tension spring 35 substituted therefor. In this modification, antifriction rollers 34 are employed instead of the fixed abutments 17 in the preceding form. By using the antifriction rollers, the strand portion 12a will be elongated uniformly throughout its length within the base with the increase of the strand tension.

The properties of strand portion 12a comply with the conditions of use, but should be commensurate with the user's capability. In a typical embodiment designed for a maximum pull of 300 pounds, for example, the nylon cord 12a is one-fourth inch in diameter, 22 feet in length, and will stretch approximately 20 inches, at which point a substantially isometric condition exists.

Claims

I claim:

1. An exercising apparatus comprising a relatively flat base for supporting the user thereon, a flexible elastic strand having one end thereof connected to said base, an elongated bar adapted to be grasped by the user at longitudinally spaced points, said bar having one end thereof terminating at and connected to the other end of said strand whereby the latter will yieldingly transmit stress from said bar to the base when the grasped bar is moved upwardly and means for damping the return of said strand from an elongated stressed position to its initial contracted unstressed position, said damping means including a second strand supported by said base and having a relatively greater elasticity than said first strand, and means frictionally engaging said second strand.

2. Exercising apparatus as defined in claim 1 and further comprising means on said base for supporting for longitudinal movement a length of said first strand adjacent its base connected end, said last-named means including a plurality of spaced stationary abutments frictionally engaged by and subdividing said last-named strand length into a plurality of shorter lengths angularly disposed relative to one another.

3. An exercising apparatus comprising a relatively flat base for supporting the user thereon, a flexible elastic strand having one end thereof fixedly connected to said base, an elongated bar adapted to be grasped by the user at longitudinally spaced points, said bar having one end thereof terminating at and connected to the other end of said strand, and means carried by said base and disposed substantially in a plane parallel to the upper surface of the base for supporting for longitudinal movement a length of said strand adjacent its fixed end portion, said strand supporting means including a plurality of spaced stationary abutments frictionally engaged by and subdividing said last-named strand length into a plurality of shorter lengths angularly disposed relative to one another.